Method of and means for the magnetic separation of materials



Feb. 20, 1934.

a. GRANIGG 1,948,419

METHOD OF AND MEANS FOR THE MAGNETIC SEPARATION OF MATERIALS Filed June 10, 1950 Patented Feb. 20, 1934 METHOD OF AND ME NETIC SEPABATIO Bartel Gram,- Application Claim.

This invention relates to an improvement or the known process for the separation of goods or moteriols occording to which the separation is curried out by means of roller-shaped iron bodies s which ore unnulerly subdivided endure caused to revolve in the held of o stationary system of mognets end of means for the corrying out of this improved process. The separators operating occording to the known process are only employuble in connectlonwith groded goods or materiel, which letter must moreover be delivered into the seporotor either in the dry state or in a. stream oi water for the purpose of obtoining tolerably useful results.

in occordoncc with the present invention the seporetion is efiected in the following manner. The goods or material to be separated are caused to travel in on cxiol direction through o magnetic field by moons oi o conveyor-helix which itself iorms one or the magnetic poles. This oxiol conveyance of the materiel through the cops-- rotor enables the some to be continuously rolled about, so that so the fragments and particles of the muteriel to be separated come in contact with the rnognetired helix, this eli'ect being increased by the fact that the separate turns of the helix are brought to beer in succession on the some material, whereby it cumulative or repeatin action is uchieved. It thus becomes possible with this improved process to charge the sepsrotor with ungreded material and to separate slimy, dry, or moist material with equal efllciency. The practical application of this process can be accomplished by means of a variety of devices, or which a few examples will be discussed and described in the following specification.

For the purpose of obtaining the field strengths required for the separating out of weekly magnetic material the helix is mounted, in accordance 40 with the invention; on an axle consisting of material which is a good magnetic conductor, this axle being in its turn mounted in a longitudinally slotted iron cylinder. For the present purpose the helix consists of magnetic material and can have one or more turns, magnetizing coils being employed to magnetlze the entire system in such a manner that the helix constitutes the one pole while the surrounding portion of the iron cylinder constitutes the other pole. In this manner an exceedingly powerful magnetic field is formed between the helix and the casing which is capable of causing even ieebly magnetic material to clingto the surface of the helix. For the purpose of increasing the magnetlc effect the outer edge of the helix may June 10, 1930, Serial No. in Austria September 2, 192

ANS FOR THE MAG- N OF MATERIALS llcoben, Austria 430.347, and

be flssured throughout its length so as to present a Y-shaped cross-section, or the helical edge may also be given a particulerlv adventageous pole shape by the provision thereon oi o plurality of grooves or slots. As hos oireody been on mentioned the material is moved through the opperetus in an axial direction during the process oi separation. This function of the inognetised helix is reinforced by further non-magnetic con veyor-spirals provided specially for this purpose. on A further measure for the purpose of intensity ing the mixing and hreehinguip oction oi the spirols consists in the providing oi odditionei mixing arms. It is also possible to the por tion of the separator traversed by the materiel with water and to allow the sepcrotor to worii: in standing (stagnant) water, by which moons even the most minute magnetic porticies con be extracted from'the upgraded materiel. The sepsrator con also work with running terial being caused to troverse t a stream of water or other liquid. in the oppo rotus required for the carrying out of this prior-- ciple the material, which is conveyed by the helix in an axial direction, is submitted to the process of seporation several times in succession. it is also possible by the reduction of the diameter of some of the turns of the helix to increase at will the strength of the held and therewith the sensitiveness oi the seporetor, or to carry out a separation of strongly and ieebly mag netic material in one process and in one end the same separator;

Instead of a simple spiral or helical surface multiple helices can be employed. Finally it is possible to divide the cylinder longitudinally and to employ the two halves of the cylinder, between which the'helix rotates, as pole shoes.

In each oi these cases instead of the helix with continuous spiral turns separate blades resembling those of a. propeller can be employed.

The delivery of the magnetic material lifted by the helix is eifected either automatically by allowing the material to become detached in consequence of centrifugal force or or the force of gravity in the slotted open portion of the cylinder, or by the provision of scrapers or a magnetic shunt. For this purpose the scraper can be caused'to engage in the turns of the helix, end is to this end slotted or comb-shaped and takes the form of an endless strip for the purpose 0! being able to pa'rtlcpitate in the movement or the helix.

Several forms of construction em dying the he seporotor in writer, the too-- invention are shown in the accompanying drawing, in which:-

Fig. 1 shows a helical separator diagrammatically in longitudinal section. Fig. 2 is a cross-section through the delivery opening, while Figs. 3 and 5 illustrate other practical modifications of the helix, likewise in longitudinal section. v

Fig. 4 shows a delivery device.

Fig. 6 shows diagrammatically a further type of helix in cross-section.

The magnetizable axle 1 is mounted in an iron casing 2 closed except for a slot. On the axle 1 there is keyed the magnetic helix 3 which is magnetized by the coils 4 encircling the axle. The charging opening for the material for separation is denoted by the reference character 5, and is shown in the drawing for the sake of clearness in the upper portion of the casing 2, while in practice this opening is usually provided on a level with the axle. 6 denotes the delivery open ing at the bottom of the casing 2. The scraper '7 (Fig. 2) is located in a slit 8 in the casing 2 and serves for the delivery of the magnetic material separated in the apparatus. A magnetic shunt 9 connects the scraper 7 withthe adjacent portion of the casing 2 and thus weakens the magnetism of the helix in the region of the delivery opening. Fig. 1 shows at 10 a conveyorhelix of non-magnetic material which is inserted between the windings of the helix 3. In the form of construction for the helix shown in Fig. 3 the helix 3 is fissured as to its outer edge, so that two poles 3' and 3" are formed. A non-magnetic helix 10' for the conveyance of the material can further be inserted between the poles 3' and 3".

For the purpose of weakening the action of the helix at the point of entry of the material for separation and of enabling the powerfully magnetic material only to be separated out first the initial turns 11 and 12 of the helix 3 are of smaller diameter than the succeeding turns, as will be seen from Fig. 5. In addition, the helix may be designed with fissures as shown in Fig. 3, to form poles 3, 3" and a non-magnetic helix 10'.

A delivery device serving for the scraping oil of the magnetic material is shown in Fig. 4, and consists of a metallic strip 13 which runs over rollers 14 and is provided at one side with recesses 15 in which the turns of the helix 3 engage.

Fig. 6 shows a further development of the helix according to which the helix does not possess a continuous outer edge but is resolved into a number of fan-like portions 19 with suitably twisted blades 20.

For the magnetizing of the system apart from direct current any kind of alternating current may be employed.

I claim:--

1.' The process of separating materials of different magnetic permeability which consists in generating a helical magnetic field the lines of force of which run radially, rotating the said field around its axis, introducing the said materials into the said field at one end thereof, mechanically conveying the said material continuouslytowards the other end of the said field, lifting out the magnetizable particles of the said material from the remainder thereof by magnetically conveying the same for rotation with the said field, weakening the said field along a fixed region crossing the thread of the rotating ":5 helical field, detaching the said particles in the said region from the said fieidand dicharging the said particles from the said field intermediate the two ends thereof, and mechanically discharging the said remainder from the said field at the opposite end thereof to that at which the said materials are introduced.

2. A device for separating materials of difierent magnetic permeability, comprising in combination with a slotted iron casing an axle of magnetic material adapted to be rotated within the said casing, a helical body or bodies attached to the said axle, magnetic connection between the said axle and the said casing, and means, such as coils, for magnetizing the said helical body or bodies, the said means being so disposed that the outer edge of the said helical body or bodies constitutes the pole of a magnetic system the lines of force of which traverse the gap between the said outer edge and the said casing.

3. The combination claimed in claim Zwith the outer edge of the helical body or bodies cleft throughout its length, so that a multiple pole is formed, for the purpose of increasing the mag= netic effect.

4. The combination claimed in claim 2 with 26%) the individual turns of the said helical body or bodies being of increasing diameters measured from the entrance of the material to the discharge or thenon-magnetizable remainder thereof for the purpose of weakening the action of 2% the magnetic field at the point of entry of the material for separation and of enabling the powerfully magnetic material only to be separated out first.

5. The combination claimed in claim 2 with lid the individual turns of the said helical body or bodies being oi. increasing diameters measured from the entrance of the material to the discharge of the non-magnetizable remainder thereof for the purpose of weakening the action of the i2 6 magnetic field at the point of entry of the material for separation and of enabling the powerful ly magnetic material only to be separated out first, the outer edge of the said turns being cleilt throughout its length, so that a multiple pole is formed, for the purpose of increasing the magnetic effect.

6. A device for separating materials of different magnetic permeability, comprising in com" binationwith a slotted iron casing an axle of 712 53 magnetic material adapted to be rotated within the said casing, a helical body or bodies of magnetic material attached to the said axle, magnetic connection between the said axle and the said casing, means for magnetizing the said helical no body or bodies disposed about the said axle,

and a helical body or bodies of non-magnetic material attached to the said rotating magnetic body or bodies as a projecting ridge adapted to aid the movement of the material.

'7. The combination claimed in claim 2 with a cleft longitudinally of the outer edge of the turns of the said helical body or bodies, and a comveyfir-helix of non-magnetic material in the said 0 e 8. The combination claimed in claim 2 with spokes between the said helical body or bodies and the said axle, and magnetizing coils embracing the said spokes and adapted to magnetize the adjacent turns of the said helical body or bodies in such a manner that a magnetic flux is set up between the outer edges, respectively, of the said adjacent turns.

9. A device for separating materials of different magnetic permeability, comprising in com- 10. The combination claimed iii claim 2 with a scraper 'i'or the detachment o1 magnetic parti-' cles from the said helical body or bodies consisting 01' an endless comb-shaped strip adapted to engage the turns of the said helical body or bodies.

IBIAR'I'EL GRANIGG.

ias 

